JPH089403Y2 - Engine cam cover device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine cam cover device.

(Prior Art and Problems Thereof) In order to achieve high performance in automobile engines and the like, a DOHC engine having two camshafts on a cylinder head and driving an intake / exhaust valve separately has become popular.

As a conventional DOHC engine, for example, as shown in FIG. 4, a cam cover 52 mounted on a cylinder head 51 is provided, a plug boss portion 53 into which a spark plug 56 is inserted in a central portion of the cam cover 52, and a screw on the cylinder head 51. A bolt boss portion 55 for inserting a mating bolt 54 is integrally formed.

By integrally connecting the plug boss portion 51 and the bolt boss portion 55, the rigidity between them is increased, and the tightening force of the bolt 54 acts evenly around the plug boss portion 53, and the cam cover 52 and the cylinder head 51 through the gasket 57. The sealability between them is secured (see Japanese Patent Laid-Open No. 167145/1986).

(Problems to be Solved by the Invention) However, since the two camshafts are arranged so as to sandwich the spark plug 56 in the cylinder head 51, the side wall of the upper wall portion 58 of the cam cover 52 that covers the two camshafts. Since the width in the direction increases, the rigidity of the thin plate-shaped upper wall portion 58 is insufficient,
There is a problem that the engine vibration causes resonance and increases noise.

The present invention aims to solve these conventional problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a cam cover mounted on the cylinder head, a plug boss portion for inserting an ignition plug into a substantially central portion of the cam cover, and a screw on the cylinder head. In the cam cover device for an engine, a bolt boss portion for inserting a mating bolt is formed at a plurality of positions along the longitudinal direction, and at least the outer peripheral portion of the cam cover and the plug boss portion seal the cylinder head. And vertical ribs that intersect with the horizontal ribs that are connected to the left and right side wall portions of the cam cover substantially orthogonal to the vertical ribs at the bolt bosses, respectively, are integrally projected downward from the upper wall portion of the cam cover, A coupling lever for integrally coupling the plug boss and the bolt boss adjacent to the plug boss. To form
In addition, a substantially annular partition wall that commonly surrounds the plug boss portion and the bolt boss portion that are adjacent to each other is formed.

(Operation) Based on the above structure, the rigidity of the entire cam cover is increased by the vertical ribs and the horizontal ribs which are orthogonal to each other in the bolt boss portion, thereby preventing generation of noise due to resonance of the upper wall portion during engine operation. It

Further, in addition to the vertical ribs and the horizontal ribs that are orthogonal to each other, a coupling rib that integrally couples the plug boss portion and the bolt boss portion adjacent thereto is provided, and a substantially annular shape that commonly surrounds the plug boss portion and the bolt boss portion. Since the partition wall is formed, the rigidity of the cross section that vertically cuts each plug boss portion and the bolt boss portion is also significantly improved, which effectively suppresses the deformation of the cam cover due to the bolt tightening force at the bolt boss portion, and the plug boss portion. The surface pressure exerted on the joints between the cylinder cover and each part of the cam cover, including the periphery, is made uniform and the sealing performance is improved.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

Cam cover 1 shown in FIGS. 1, 2, and 3, respectively.
Is provided in a 4-cylinder DOHC engine, and an ignition plug is arranged in the center of each cylinder, and two camshafts are arranged on both sides of each ignition plug.

The cam cover 1 is integrally molded in a box shape that covers the cylinder head with an aluminum alloy, a joint flange 2 for the cylinder head is formed at the lower end of the outer periphery, and a plug boss portion 3 into which a spark plug of each cylinder is inserted is formed in the central portion. , 4,5,6
Are integrally formed.

Bolt holes 7 are formed in the four corners of the joint flange 2 and between the # 1 cylinder and the # 2 cylinder and between the # 3 cylinder and the # 4 cylinder, and the bolt holes 7 are inserted into the respective bolt holes 7. Bolts are screwed onto the cylinder head to fasten the cam cover 1 to the cylinder head. In addition, the joint flange 2 is formed with a groove 8 for interposing a gasket over the entire circumference.

Bolt boss portions 9, 10, 11 are formed on the cam cover 1 in the vicinity of the plug boss portions 3, 4, 6, respectively. The bolts that pass through the bolt boss portions 9, 10 and 11 are screwed into the cylinder head, and the plug boss portions 3, 4, 5 and 6 are pressed against the cylinder head. Each plug boss 3,4,5,6 and each bolt boss
A step portion 12 is formed around 9,10,11, and a gasket is provided on the step portion 12 to connect the plug boss portions 3,4,5,6 and the bolt boss portions 9,10,11 to the cylinder head. Is designed to be sealed.

Connecting ribs 13, 14, 15 for connecting the plug boss portion 3 and the bolt boss portion 9, the plug boss portion 4 and the bolt boss portion 10, and the plug boss portion 6 and the bolt boss portion 11 to each other are integrally projected from the upper wall portion 16 of the cam cover 1. . Each connecting rib 13,1
The lower end surfaces of the reference numerals 4 and 15 are stepped portions 12 in which the gasket is interposed.
Is configured.

Around the plug bosses 4, 5 and 6, annular partition walls (ribs) 17, 18 and 19 integrally projecting from the upper wall 16 are formed, and the left and right side walls 21 and 22 of the cam cover 1 and the rear side. Partition walls 24 are formed in the wall portion 23 and the plug boss portion 3 at a predetermined interval, and a plate (not shown) is joined to the lower end surfaces of the respective partition walls 17, 18, 19, 24, and between the plate and the upper wall portion 16. To define a separator chamber having a predetermined volume. This separator chamber communicates with the intake pipe of the engine through a pipe (not shown), and the blow-by gas blown through the gap between the cylinder and the piston into the crank chamber is recirculated through the separator chamber.
The oil contained in the blow-by gas is separated in the separator chamber. Reference numeral 26 in the drawing denotes a bolt boss portion for fastening the plate.

A lateral rib 28 extending from the bolt boss portion 9 to the left and right side wall portions 21 and 22 is integrally projected on the upper wall portion 16 of the cam cover 1. An opening boss portion 29 for supplying engine oil is integrally formed in the middle of the lateral rib 28.

Similarly, on the upper wall portion 16, from the bolt boss portion 10 to the left and right side wall portions.
A horizontal rib 31 extending over 21,22 is integrally projected.

Similarly, the upper wall portion 16 includes side wall portions on the left and right from the bolt boss portion 11.
A horizontal rib 42 extending over 21, 22 is integrally projected.

Recesses 33, 34, 35, 36 are formed in the left and right side walls 21, 22 so as to surround the bolt hole 7, respectively.

Two horizontal ribs 38, 39 extending integrally so as to connect the concave portions 33, 35 facing each other are integrally projected on the upper wall portion 16.

Similarly, the upper wall 16 is integrally formed with a lateral rib 41 extending so as to connect the concave portions 34 and 36 facing each other.

The lateral ribs 28, 38, 39, 31, 41, 42 are orthogonal to the cylinder row direction and partition walls that define a separator chamber.
It projects at a predetermined height lower than 17,18,19,24.

The upper wall portion 16 is integrally formed with a vertical rib 43 which extends from the plug boss portion 3 to the horizontal rib 38 so as to intersect the bolt boss portion 26.

Similarly, the upper wall portion 16 includes a lateral rib 39, an annular partition wall 17, a plug boss portion 4, bolt boss portions 10 and 26, an annular partition wall 18, a plug boss portion 5, a rib 41, an annular partition wall 19, a plug boss portion 6 and a bolt boss portion 11 respectively. Vertical ribs that intersect and extend to the rear wall 23
44 is projected integrally.

The vertical ribs 43, 44 extend in the cylinder column direction in the central portion of the cam cover 1 and are orthogonal to the horizontal ribs 28, 38, 39, 31, 41, 42, and each partition wall 17 defining a separator chamber. , 18,
It projects at a certain height lower than 19,24.

 Next, the operation will be described.

Vertical ribs 4 orthogonal to each other are provided on the upper wall portion 16 of the cam cover 1.
By integrally projecting the 3,44 and the lateral ribs 28,38,39,31,41,42, the rigidity of the upper wall portion 16 can be significantly increased, and the upper wall portion 16 resonates due to engine vibration. It can be prevented from being awakened and increasing noise.

Connecting ribs that intersect the vertical ribs 43, 44 with the plug boss portions 3, 4, 5, 6 respectively, and integrally connect the plug boss portions 3, 4, 6 with the bolt boss portions 9, 10, 11 adjacent to them. 13,
By forming 14 and 15, respectively, the cam cover 1 has a significantly increased rigidity in the direction in which the plug boss portions 3, 4, 5 and 6 are cut longitudinally, and effectively suppresses the deformation of the cam cover 1 due to the tightening force of the bolts. The surface pressure acting on the joint between the plug bosses 3, 4, 5 and 6 and the cylinder head can be made uniform to improve the sealing performance.

(Effects of the Invention) As described above, according to the present invention, the cam cover mounted on the cylinder head is provided, and the plug boss portion into which the ignition plug is inserted and the bolt to be screwed into the cylinder head are inserted into the substantially central portion of the cam cover. In a cam cover device for an engine in which a bolt boss portion is formed at a plurality of positions along the longitudinal direction, and at least the cam cover outer peripheral portion and the plug boss portion seal against the cylinder head, a vertical rib intersecting the plug boss portion is provided. ,
Lateral ribs that are substantially orthogonal to the vertical ribs and connect to the left and right side wall portions of the cam cover are integrally protruded downward from the upper wall portion of the cam cover at the bolt boss portion, and are close to the plug boss portion. Since the connecting ribs that integrally connect the bolt boss portion and the plug boss portion and the bolt boss portion that are adjacent to each other are formed to form a substantially annular partition wall, the upper wall portion of the cam cover is formed during engine operation. The noise generated due to resonance can be reduced, and the surface pressure that acts on the joint between the cam cover and the cylinder head at the time of fastening is made uniform to improve the sealing performance, and the leakage of oil and blow-by gas from the outer periphery of the cam cover and the plug boss is ensured. Can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view from above of a cam cover showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a plan view from below. FIG. 4 is a longitudinal sectional view of a cam cover and a cylinder head showing a conventional example. 1 ... Cam cover, 3,4,5,6 ... Plug boss part, 9,10,11 ... Bolt boss part, 13,14,15 ... Coupling rib, 16 ... Upper wall part, 21,22
… Side walls, 28, 38, 39, 31, 41, 42… Horizontal ribs, 43, 44… Vertical ribs.

Claims (1)

[Scope of utility model registration request] 1. A cam cover mounted on a cylinder head, wherein a plug boss portion into which a spark plug is inserted and a bolt boss portion into which a bolt to be screwed into the cylinder head is inserted are provided in a substantially central portion of the cam cover along the longitudinal direction. In a cam cover device for an engine, which is formed at a plurality of positions at least, and seals the cylinder head with at least the cam cover outer peripheral portion and the plug boss portion, a vertical rib intersecting the plug boss portion and the vertical rib at the bolt boss portion. Horizontal ribs that are substantially orthogonal to and are connected to the left and right side wall portions of the cam cover are integrally projected downward from the upper wall portion of the cam cover, and the plug boss portion and the bolt boss portion adjacent thereto are integrally formed. Forming a connecting rib for connecting to the plug boss and the bolt Cam cover device for an engine is characterized in that to form a substantially annular partition wall surrounding the parts in common.